The invention relates to a method for positioning a magnetic head to various tracks of a magnetic tape in a magnetic tape recorder wherein the magnetic head is positioned to the various tracks perpendicular to a moving direction of the magnetic tape by use of a positioning device provided with an electric motor.
German OS No. 32 44 149, corresponding to U.S. Pat. No. 4,609,959, incorporated herein by reference, discloses an arrangement for positioning a magnetic head to various tracks of a magnetic tape wherein the magnetic tape is accommodated in a cassette which is inserted into the magnetic tape recorder in a longitudinal direction. The magnetic tape is moved in a longitudinal direction by use of a tape drive capstan, and the recording occurs on a plurality of parallel tracks by use of a magnetic head. The magnetic head is provided, for example, with two write/read heads arranged above one another and the recording occurs, for example, in four parallel tracks. The magnetic head is positioned to the various tracks by use of a positioning device. The positioning device contains a stepping motor at which a worm gearing is situated, this worm gearing cooperating with a screw gearing via which a magnetic head carrier accepting the magnetic head is shifted perpendicular to the moving direction of the magnetic tape.
Although precise component parts are used for the positioning device, a deviation of a write/read head of up to .+-.40 .mu.m from the precise center of a track is possible when the magnetic head is positioned at the outer tracks. In magnetic tape recorders having a low number of tracks, this deviation does not present any difficulties in the recording or playback of signals. When, however, the number of tracks on the same magnetic tape is increased to, for example, 8 or even 20, such tolerances of .+-.40 .mu.m can no longer be accepted.